Microstructure and properties of AlCoCrFeNi2.1 eutectic high-entropy alloy formed by laser melting deposition (LMD)

Abstract

In this study, laser melting deposition (LMD) was used to form AlCoCrFeNi2.1 eutectic high-entropy alloys (EHEAs) to solve the formability problems. EHEAs were prepared with laser power of 600 W, scanning rate of 4 mm/s, powder feeding rate of 8 g/min. The microstructure and mechanical properties of the as-deposited alloy and the as-cast alloy were evaluated. The eutectic structure containing L12 and B2 phases is retained and grows along the deposition direction to form a characteristic herringbone structure. This characteristic structure makes the mechanical properties of the as-deposited alloy (σb = 1097 ± 9 MPa, δ = 22 ± 2% in vertical; σb = 996 ± 6 MPa, δ = 14 ± 2% in horizontal) are significantly improved compared to the as-cast alloy (σb = 980 ± 6 MPa, δ = 14 ± 2%).